There exists a need for access between floors of buildings where there is not room of the need for permanent access structure such as stairways, elevators or escalators. Examples of such a need are an attic in home, an overhead storage area in a garage, or an overhead storage loft in a warehouse. In these and other similar cases there is occasional need for access to an upper area but it is desirable for the access means to be out of the way most of the time so that the lower floor area can be used for other activities. Therefore a permanent structure is not an acceptable alternative. What is needed is an access means between floors that can be readily used but also readily stored out of the way when not in use.
Such temporary access between floors has been addressed in U.S. Pat. No. 1,930,992 to Bessler which has a stairway that rolls down a hinged access panel in the upper floor. The movement of the stairway is powered by an electric motor through a system of cables and pulleys.
In U.S. Pat. No. 2,931,456 to Harmon a system of gears, cables pulleys is used to move a stairway between floors but the stairway is guided by a pair of curved handrails that each pass between a pair of guide wheels. The shape of the handrails determine the motion profile of the stairway.
In U.S. Pat. No.3,789,955 to Knapp a stairway is moved through a rack and pinion by an electric motor and slides on a hinged ceiling panel.
Other material of background interest is in U.S. Pat. No. 1,636,279 to Bessler, U.S. Pat. No. 1,636,280 to Bessler, U.S. Pat. No. 1,636,281 to Bessler, U.S. Pat. No. 1,749,409 to Bessler, U.S. Pat. No. 1,811,707, U.S. Pat. No. 1,811,709 to Bessler, and U.S. Pat. No. 1,858,981 to Bessler.